Evidence Against the Hopping Mechanism as an Important Electron Transfer Pathway for Conformationally Constrained Oligopeptides

Dipartimento di Scienze Chimiche, Università di Padova, via Marzolo 1, 35131 Padova, Italy.
Journal of the American Chemical Society (Impact Factor: 12.11). 02/2005; 127(2):492-3. DOI: 10.1021/ja043607e
Source: PubMed


The rate constant of intramolecular electron transfer through oligopeptides based on the alpha-aminoisobutyric acid residue was determined as a function of the peptide length and found to depend weakly on the donor-acceptor separation. By measuring the electron-transfer activation energy and estimating the energy gap between donor and bridge, we were able to discard the electron hopping mechanism.

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    • "lowering of the barrier for electron transmission [21] [22] [23]. As a consequence , the peptides exhibiting the secondary structure with hydrogen bonded network should promote electron transfer more efficiently comparing to non-hydrogen bonded systems like polyprolines. "
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